This application is an improvement of U.S. Pat. No. 5,505,222 entitled "Multiple-fold Automatic Umbrella with Simplified Control Means" (hereinafter defined as "Prior Art") by the same inventors of this application. However, the prior art patent has the following drawbacks:
1. The upper latch 52 of the control means 5 includes a pair of bifurcated arm members 523, each arm member 523 made as a thin plate to possibly weaken its strength.
2. The sloping spring portion 580 of the convex spring plate 58 for biasing the locking head 551 to be locked on the detent protrusion 111a in the inner tube 11 is lacking of a pair of side walls disposed on two opposite side portions of the sloping spring portion 580 for slidably holding the locking head 551 when folding the umbrella, thereby affacting a reliability for folding the umbrella.
3. For fixing the two spring ends 581, 582 deeply into the narrower inner tube 11, it will increase the assembly complexity and production cost.
The present inventors have found the drawbacks of the prior art patent and invented the present multiple-fold automatic umbrella with simplified reliable control means.